Abstract: Imagine a world in which the ordinary effects of human activities protect and restore the environment, whether or not people are even aware of it. This world is not fanciful; it is the world our species must foster if we are to get through coming decades without considerable pain. It is also achievable if we apply and elaborate the principles contained in the concept of sustainable development.

Sustainable development is an internationally recognized framework for integrating development with environmental protection. In the international context where the term arose, development is a way of fostering human quality of life through peace and security, economic development, and human rights. "Sustainable" modifies the term to include another goal – environmental protection and even restoration. The term is normative, not descriptive. It includes a set of principles, including the precautionary principle, integrated decision making, and intergenerational equity, for reconciling environment and development goals.

Sustainable development matters because it raises difficult and challenging questions that have received too little attention. Despite the growing global economy, there is abundant and growing evidence that the world's natural resources and ecosystems are continuing to deteriorate. Achieving sustainable development will require us to, among other things, make order-of-magnitude improvements in the efficiency with which humans use materials and energy; use legal instruments in addition to regulation (including the repeal of certain subsidies) for environmental protection; create a more mutually supportive relationship between trade and environment; and provide significant assistance to developing countries.